Are centrosomes located near the centrioles?

Answer 1

The centrosome is the main microtubule organizing center (MTOC) of the cell as well as a regulator of cell-cycle progression. It was discovered in 1888 by Theodor Boveri and was described as the 'especial organ of cell division.' Although the centrosome has a key role in efficient cell division, it has been recently shown that it is not necessary [1].

Centrosomes are composed of two orthogonally arranged centrioles surrounded by an amorphous mass of pericentriolar material (PCM). The PCM tethers proteins responsible for microtubule nucleation and anchoring, γ-tubulin, pericentrin and ninein. Each centriole is comprised of nine triplet microtubule blades in a pinwheel structure as well as centrin, cenexin and tektin [1].